content: /* ===========================================================
   * JFreeChart : a free chart library for the Java(tm) platform
   * ===========================================================
   *
   * (C) Copyright 2000-2012, by Object Refinery Limited and Contributors.
   *
   * Project Info:  http://www.jfree.org/jfreechart/index.html
   *
   * This library is free software; you can redistribute it and/or modify it
   * under the terms of the GNU Lesser General Public License as published by
   * the Free Software Foundation; either version 2.1 of the License, or
   * (at your option) any later version.
   *
   * This library is distributed in the hope that it will be useful, but
   * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
   * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
   * License for more details.
   *
   * You should have received a copy of the GNU Lesser General Public
   * License along with this library; if not, write to the Free Software
   * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301,
   * USA.
   *
   * [Oracle and Java are registered trademarks of Oracle and/or its affiliates.
   * Other names may be trademarks of their respective owners.]
   *
   * ---------------
   * XYDataItem.java
   * ---------------
   * (C) Copyright 2003-2012, by Object Refinery Limited.
   *
   * Original Author:  David Gilbert (for Object Refinery Limited);
   * Contributor(s):   -;
   *
   * Changes
   * -------
   * 05-Aug-2003 : Renamed XYDataPair --> XYDataItem (DG);
   * 03-Feb-2004 : Fixed bug in equals() method (DG);
   * 21-Feb-2005 : Added setY(double) method (DG);
   * ------------- JFREECHART 1.0.x ---------------------------------------------
   * 30-Nov-2007 : Implemented getXValue() and getYValue(), plus toString() for
   *               debugging use (DG);
   * 10-Jun-2009 : Reimplemented cloning (DG);
   * 16-Jun-2012 : Removed JCommon dependencies (DG);
   *
   */
  
  package org.jfree.data.xy;
  
  import java.io.Serializable;
  
  import org.jfree.chart.util.ObjectUtilities;
  
  /**
   * Represents one (x, y) data item for an {@link XYSeries}.  Note that
   * subclasses are REQUIRED to support cloning.
   */
  public class XYDataItem implements Cloneable, Comparable<XYDataItem>, Serializable {
  
      /** For serialization. */
      private static final long serialVersionUID = 2751513470325494890L;
  
      /** The x-value (<code>null</code> not permitted). */
      private Number x;
  
      /** The y-value. */
      private Number y;
  
      /**
       * Constructs a new data item.
       *
       * @param x  the x-value (<code>null</code> NOT permitted).
       * @param y  the y-value (<code>null</code> permitted).
       */
      public XYDataItem(Number x, Number y) {
          if (x == null) {
              throw new IllegalArgumentException("Null 'x' argument.");
          }
          this.x = x;
          this.y = y;
      }
  
      /**
       * Constructs a new data item.
       *
       * @param x  the x-value.
       * @param y  the y-value.
       */
      public XYDataItem(double x, double y) {
          this(new Double(x), new Double(y));
      }
  
      /**
       * Returns the x-value.
       *
       * @return The x-value (never <code>null</code>).
       */
      public Number getX() {
          return this.x;
      }
  
      /**
       * Returns the x-value as a double primitive.
       *
       * @return The x-value.
       *
       * @see #getX()
       * @see #getYValue()
       *
       * @since 1.0.9
       */
      public double getXValue() {
          // this.x is not allowed to be null...
          return this.x.doubleValue();
      }
  
      /**
       * Returns the y-value.
       *
       * @return The y-value (possibly <code>null</code>).
       */
      public Number getY() {
          return this.y;
      }
  
      /**
       * Returns the y-value as a double primitive.
       *
       * @return The y-value.
       *
       * @see #getY()
       * @see #getXValue()
       *
       * @since 1.0.9
       */
      public double getYValue() {
          double result = Double.NaN;
          if (this.y != null) {
              result = this.y.doubleValue();
          }
          return result;
      }
  
      /**
       * Sets the y-value for this data item.  Note that there is no
       * corresponding method to change the x-value.
       *
       * @param y  the new y-value.
       */
      public void setY(double y) {
          setY(new Double(y));
      }
  
      /**
       * Sets the y-value for this data item.  Note that there is no
       * corresponding method to change the x-value.
       *
       * @param y  the new y-value (<code>null</code> permitted).
       */
      public void setY(Number y) {
          this.y = y;
      }
  
      /**
       * Returns an integer indicating the order of this object relative to
       * another object.
       * <P>
       * For the order we consider only the x-value:
       * negative == "less-than", zero == "equal", positive == "greater-than".
       *
       * @param dataItem  the object being compared to.
       *
       * @return An integer indicating the order of this data pair object
       *      relative to another object.
       */
      @Override
      public int compareTo(XYDataItem dataItem) {
         int result;
  
          double compare = this.x.doubleValue()
                           - dataItem.getX().doubleValue();
          if (compare > 0.0) {
              result = 1;
          }
          else {
              if (compare < 0.0) {
                  result = -1;
              }
              else {
                  result = 0;
              }
          }
  
  
          return result;
  
      }
  
      /**
       * Returns a clone of this object.
       *
       * @return A clone.
       */
      @Override
      public Object clone() throws CloneNotSupportedException {
          return super.clone();
      }
  
      public XYDataItem copy() {
          try {
              return (XYDataItem) clone();
          } catch (CloneNotSupportedException e) {
              return null;
          }
      }
  
      /**
       * Tests if this object is equal to another.
       *
       * @param obj  the object to test against for equality (<code>null</code>
       *             permitted).
       *
       * @return A boolean.
       */
      @Override
      public boolean equals(Object obj) {
          if (obj == this) {
              return true;
          }
          if (!(obj instanceof XYDataItem)) {
              return false;
          }
          XYDataItem that = (XYDataItem) obj;
          if (!this.x.equals(that.x)) {
              return false;
          }
          if (!ObjectUtilities.equal(this.y, that.y)) {
              return false;
          }
          return true;
      }
  
      /**
       * Returns a hash code.
       *
       * @return A hash code.
       */
      @Override
      public int hashCode() {
          int result;
          result = this.x.hashCode();
          result = 29 * result + (this.y != null ? this.y.hashCode() : 0);
          return result;
      }
  
      /**
       * Returns a string representing this instance, primarily for debugging
       * use.
       *
       * @return A string.
       */
      @Override
      public String toString() {
          return "[" + getXValue() + ", " + getYValue() + "]";
      }
  
  }
  